This means that the cleanup code will only run if there are players in the lobby, arena, or spectator area. This fixes the first part of #435 where the cleanup code is taking too long for large/many arenas. Originally, the force end command was meant as a way to circumvent any condition keeping players from leaving the arena and cleaning it up. In retrospect, the main reason for using force end is to "get people out of there", but since there's plenty of stuff that can go wrong when a player leaves, this isn't really that helpful, as exceptions will just cause the command to break at the same point anyway.
MobArena

MobArena is an arena-style minigame for Spigot-based Minecraft servers
Getting Started
If you don't want to compile the plugin yourself, grab a release artifact from one of these two sites:
The wiki here on Github should have all the information you need to get started using the plugin.
Getting Help
If you run into problems or need help with something, feel free to hop on IRC (#mobarena @ irc.esper.net) to have a chat. If you don't know what IRC is or don't have an IRC client, you can use a web-based one:
Remember, though, that IRC is idle chat, which means you likely won't get a response immediately. It could take anything from a couple of seconds to a day, but your message will be seen.
Bugs and Suggestions
Found a bug or have a great idea for the plugin? Use the issue tracker here on Github to submit a bug report or feature request. Please have a look through the existing issues before you post a new one to avoid duplicates.